Bicyclic heterocycle-containing sulfonamide compounds are useful as antitumor agents, and among them, N-(3-chloro-1H-indol-7-yl)-4-sulfamoylbenzenesulfonamide (hereafter sometimes abbreviated as Compound (1)) exhibits remarkable antitumor activity (see Patent Document 1), activated lymphocyte suppressive action (see Patent Document 2), or eating enhancement action (see Patent Document 3).

The compound (1) is a known compound, and a production method thereof is disclosed in Example 19 of Patent Document 1. The document describes “ . . . to give 349 mg of the title compound. . . . (recrystallized from ethanol-n-hexane)”. It discloses only a melting point and a nuclear magnetic resonance spectrum thereof as physical properties of the crystal, but does not disclose or suggest the existence of crystal polymorphs other than the above description of crystal.
Patent Document 1: International Publication WO 95/07276 pamphlet
Patent Document 2: International Publication WO 03/022271 pamphlet
Patent Document 3: International Publication WO 03/022272 pamphlet